The utilization of fuel cell power plants to operate electric vehicles, particularly private passenger vehicles, requires that the fuel cell power plant be able to fit within space that is available in the vehicle. To help maximize the fuel cell stack volume that can be accommodated in smaller vehicles, the use of two fuel cells mounted side by side is one plausible solution. However, if there are two separate fuel cell stacks in a power plant, then the amount of external plumbing required to supply the fuel and oxidant reactant gases and carry off the exhaust thereof must be doubled, one set for each fuel cell.